In 2019, when Sophie* was 12, her classmates sent her “extreme and traumatising” videos that included an al-Qaida beheading, pornography and bestiality. She recalls an adult player in an online game persuading her to meet in person. Although her dad worked in IT, looking back she thinks: “My parents’ generation simply didn’t have a clue.” Now aged 18 and a student at the University of Edinburgh, she wouldn’t allow her children to have a smartphone until they’re adults. “As a teen I would have been the biggest advocate on everyone having a phone, but I’ve 100% changed my opinion,” she...